When rekeying a lock assembly having a traditional cylinder design, the user is required to remove the cylinder plug from the cylinder body and replace the appropriate pins so that a new key can be used to unlock the cylinder. This typically requires the user to remove the cylinder mechanism from the lockset and then disassemble the cylinder to some degree to remove the plug and replace the pins. This requires a working knowledge of the lockset and cylinder mechanism and is usually only performed by locksmiths or trained professionals. Additionally, the process usually employs special tools and requires the user to have access to pinning kits to interchange pins and replace components that can get lost or damaged in the rekeying process. Finally, professionals using appropriate tools can easily pick traditional cylinders.
Various locks have been designed in an effort to overcome these problems. One design is disclosed herein and allows a user to rekey a lock cylinder without removing the lock plug from the cylinder body or even removing the lock cylinder from the knob, lever or deadbolt in which it's installed. To rekey the lock cylinder described herein, a user inserts a first valid key in the keyway (home position) and rotates it about 90° to a rekeying position. The user then inserts a reset tool into the lock face, as illustrated in FIG. 54, to reconfigure the lock cylinder to a learn mode. While the lock cylinder is in the learn mode, the user removes the first valid key, replaces it with a second valid key and rotates the second valid key back to the home position. The process of rotating the key back the home position releases the lock cylinder from the learn mode and resets the lock cylinder to conform to the bitting of the second valid key. At this point, the first valid key no longer operates the lock cylinder.
Unfortunately, such a lock cylinder can be rendered inoperable if the user does not fully insert the second valid key in the keyway when the lock is in the learn mode. The reason for this is based in the way a lock works. As is known in the art, keys have certain key cuts at different positions along the key blade (bitting). The depth of a key cut is typically numbered from 0 to 6, with 0 being flush with the top of the key blade and 6 being the deepest cut. In the lock cylinder disclosed herein, the key bitting determines the positioning of pins. When a valid key is inserted, the pins are positioned to release a locking bar, allowing the lock plug to rotate within the cylinder body, thereby retracting a latch or deadbolt. If the second valid key is not fully inserted during the rekeying process, the pins will not be set to conform to the bitting of the second valid key, resulting in a blown cylinder.
To aide in recovering a lock cylinder from a blown condition, a manual reset tool was developed, as described herein and illustrated in FIGS. 31-34. With the lock cylinder removed from the knob or deadbolt, the reset tool is inserted into the bottom of the cylinder body to manually position the pins to release the locking bar. Simultaneously, a bracing tool is inserted into an aperture in the side of the cylinder body to displace the locking bar (FIG. 40) and allow the plug body to rotate in the cylinder body to the rekeying position. A learn tool is then inserted into an aperture in the face of the lock cylinder to configure the lock cylinder to the learn mode. Once in the learn mode, the reset tool and bracing tool are removed and a valid key is inserted in the keyway and returned to the home position, thereby resetting the lock cylinder to the valid key.
One difficulty with the manual reset tool is the need for serious manual dexterity in managing the lock cylinder, the reset tool and the bracing tool, while inserting a learn tool in the face of the lock cylinder and inserting a key in the keyway and rotating the key to the rekeying position.